An apparatus for treating a substrate includes a chamber including a space in which a substrate is treated, a support member disposed in the chamber and supporting the substrate, and a heating member for heating the substrate. The space is divided into an upper space and a lower space by the support member. The support member includes a support plate receiving the substrate, a base supporting the support plate, exposing a bottom surface of the support plate and including a cut region formed in an edge portion of the base, and an adjustment block held in the cut region and coupled to the base. The cut region fluidly connects the upper space to the lower space. The adjustment block divides the cut region into a plurality of vents.